Acceleration comparisons

[gaunt1]

Originally Posted by SadoMarxist

As far as the acceleration comparisons go, there was a nutter on WoP forums a few years ago who claimed that the ability of an aircraft to accelerate can be expressed and evaluated by something called Specific Excess Power (Ps). Furthermore, said person was audacious enough to claim that the information necessary to compare the acceleration performance of one airplane relative to another is contained within the IL- 2 Compare diagrams. I can't find the thread now, but never mind, it was long and boring anyway. However, I was able to find a document which explains Ps:

http://www.aviation.org.uk/docs/flig...-FTM108/c5.pdf

Im not good at maths at all, so how is that working? Acceleration is proportional to excess power, or exponential?
Im asking this because something is fishy with the acceleration of some aircraft, primarily the La-5FN. Compared to La-5F, it has ~12% more powerful engine, slightly lower weight, and about the same drag. But acceleration is far-far better. So either the La-5F is porked, or the La-5FN is an UFO in this regard. I suspect the latter. Because if we take the factors above into account, I think it should have only about 15-20% better acceleration, for example 270 to 500 should take about 44-48 seconds, not 36.

As far as I know VK-105 Yaks all have very good FM, so LaGG-3 S66 is also fishy, because its slightly better than even the Yak-1b. I doubt that its OK.

Correct me if Im wrong.